Electric-arc lamp



(No Model.) 3 SheetsSheet 1.

T. E. ADAMS.

ELECTRIC ARC LAMP. v No. 550,574. Patented Dec. 8,1895.

(No Model.) 3 Sheets-Sheet 2.

T. E. ADAMS.

ELECTRIC ARC LAMP. v

No. 550,574. Patented 1360.3, 1895.

UNITE STATES PATENT OFFICE.

THOMAS E. ADAMS, OF CLEVELAND, OHIO.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 550,574, dated December3, 1895.

Application filed March 14, 1895. Serial No. 541,732. (No model.)

To all whom it may concern.-

Be it known that I, THOMAS E. ADAMS, a resident of Cleveland, in thecounty of Guyahoga and State of Ohio, have invented certain new anduseful Improvements in Electric-Arc Lamps; and I do hereby declare thefollowing to be afull, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

My invention relates to an improvement in electric-arc lamps designedmore particularly for use on constant-potential circuits, one obj ect ofthe invention being to so construct the lamp that its adjustments willremain certain and fixed more permanently than has been heretoforecommon in the art.

A further object is to produce devices so constructed and arranged as toprevent the lapping of the carbon points, which would produce a shortcircuit and result in either blowing the fuse on the line when such alarge current is permitted to pass as would dangerously heat theconducting-wires or preventing the lamp from burning until the carbonsare placed in proper alignment and the damage to the fuse or linerepaired.

A further object is to so construct the friction-clutch which grasps thecarbon rods that it shall have maximum durability.

A further object is to construct the clutch in such manner that itsliability to be affected by dust and dirt will be reduced to a minimum.

A further object is to so construct the clutch of an electric-arc lampthat a carbon rod not perfectly smooth and true 011 its surface will beproperly fed and so that it shall be convenient of adjustment in thelamp and compensate for wear of the carbon rod or other parts.

lVith these objects in view the invention consists in certain novelfeatures of construction and combinations and arrangements of parts, ashereinafter set forth, and pointed out in the claims.

In the accompanying drawings, Figure l is a diagrammatical viewillustrating my invention. Fig. 2 is an elevation. Fig. 3 is ahorizontal sectional view. Fig. 3 is a section on the line as so of Fig.2. Figs. 4, 5, 6, and '7 are detail views.

A A represent the top and bottom plates of the lamp-frame, connectedtogether and properly spaced apart by means of standards A A and Brepresents the chimney. A tube a is connected with a plate a, secured tothe top plate A of the lamp-frame and extends up through the chimney B.The upper end of the tube a is screw-threaded for the reception of a nuta below which a cap a is located, said cap having a bearing on a ring a,7

attached to the upper end of the chimney, and the ring a is made withrecesses for the positive and negative leading in wires and A metallictube 1) surrounds the tube a and is electrically separated therefrom bymeans of insulating material Z). A coil O, of German silver or otherresistance material, is wound about the tube 1) and insulated from saidtube by means of interposed strips b preferably of asbestos. The coil 0is so wound that its convolutions will not be in contact with eachother, and to the upper end of the coil the leading-in wire isconnected. To the lower end of the resistance-coil a conductor a (composed, preferably, of strands of fine wire) is connected. The upper endof the conductor 0 is connected with a spring plate or adjuster 0,adapted to partially embrace the resistance-coil and have a slide-wirecontact with the convolutions of the coil. By moving the plate oradjuster 0 up or down the amount of resistance to be included in thelamp-circuit can be readily adjusted.

As shown in Fig. 2, the flexible conductor 0 can be made to move aboutthe resistancecoil, so that when the contact-plate is moved up or downand partially rotated about the resistance-coil the slack in theconductor can be compensated for.

A metallic bracket d is secured to the inn der face of the top plate Aof the lamp-frame and insulated therefrom, said bracket beingelectrically connected with the lower end of the metallic tube 1) by ashort conductor (1, and to the upper end of said metallic tube the -lleading-in wire is connected.

Fine-wire electromagnets D D are secured to the upper plate of thelamp-frame and depend therefrom. The poles f of the electromagnets Dproject some distance below the spools and are made with inner flattenedfaces f, between which an armature E is disposed, said arn'iature beingpreferably a rectangular block of iron, which also constitutes a weight,for a purpose hereinafter explained. In other words,the electromagnets Dare provided with a weighted armature.

The armature E is carried by an armaturelever E, which comprises atransverse shaft g, mounted at its ends in suitable lugs projecting fromthe standards A and arms g, the armature being secured to the free endsof the latter. An arm or bracket g is secured to the opposite side ofthe armature E, and to the free end of said arm the lower end of aplunger-rod g is pivoted, the plunger connected with said rod operatingin an air-pot g pivotally connected with the top plate A of thelamp-frame.

To the bottom plate A of the lamp-frame and at the opposite side thereoffrom the finewire magnets D D a coarse-wire magnet F is secured, thepoles h h of said magnet F being located at the ends of the core andprojecting forwardly from the spool. Between the poles h h an armature Fis disposed and secured to lugs i, projecting from the shaft 9 of thearmature-lever, said lugs being located on the opposite side of theshaft from the arms g.

The top and bottom plates A A of the lampframe are perforated for theaccommodation of the carbon or lamp rod G, said rod also passing througha perforation in the bracket (Z and into the tube a. A contact plate orbrush j is secured to the plate or bracket (1 and bears at its free endagainst the carbon rod for conduetin g the current thereto. The plate orbracket (Z is also electrically connected with one end of one of thefine-wire coils by means of a spring or spiral conductor K, the free endof the other fine-wire coil bein g connected with a conductor K by ashort spring orspiral conductor K One end of the conductor K isconnected with the lower-carbon holder of the lamp and the other end isconnected with one end of the coil of the coarse-wire magnet F, theother end of said coil being connected with the lower end of theresistanee-coil O by a wire Thus it will be seen that the coarse-wiremagnet is included in the main circuit in series and the fine-wiremagnets included in series with the coarse-wire magnet, but in ashunt-circuit around the are.

In tracing the main circuit through the lamp it will be seen that thecurrent enters at and passes through the tube I), then through theconductor (Z to the bracket (1, then to the carbon or lamp rod G throughthe contact plate or brush j, thence through the upper carbon to thelower carbon, thence through the latter and its holder, and thencethrough the conductor K to one end of the helix of the coarse-wiremagnet. From the other end of said helix the current passes through wire70 to the resistance-coil C, then through the conductor 0 and plate 0,and then through more or less of the convolutions of said coil 0, andfinally out at The path of the shunt-circuit will be traced as follows:From the bracket d a portion of the current will pass through the springor conductor K, then through the helices of the fine-wire magnets, andthen by the conductor K to the wire K, which latter is connected withone end of the helix of the coarse-wire magnet.

The carbon or lamp rod G passes through a clutch device H, theconstruction of which will now be explained. The saddle 1 of the clutchembraces the carbon rod G and is so constructed as to have an extendedbearing thereon. From opposite sides of the saddle ears 2 project,between which the clutchlever 3 is eccentrically pivoted by means'of apin a, and at its pivoted end is bifurcated for the reception of aclutch-shoe 5, which is pivotally connected to said lever by means of apin 6 passing through the contracted upper end of an angular orsquare-cornered slot '7, made in the shoe 5, the pin 4:, which pivotsthe lever to the ears of the saddle, passing through the larger end 8 ofsaid slot. Thus it will be seen that the shoe 5 will be permitted tomove on its fulcrum a distance permitted by the width of the widerportion of the slot 7, which will be sufficient to cause the clutch tograsp or release the carbon rod. If a round pin 6 be passed through around hole 00 in the shoe 5 of larger diameter than the pin, the normalposition of rest will be as shown in Fig. 7, and when strain is appliedthe position of the pin in the slot would be as shown in Fig. 6. Thischange of position is lost motion, which is very undesirable in a clutchdevice for an electric-arc lamp. By making the portion of the slot 7through which the pin 6 passes angular, as shown in Fig. 5, the positionof the pin in the angular slot '7 will always be the same, either forposition of rest or strain, and, again, by making the slot 7 in themanner above explained clogging by dust and dirt will be prevented. Myimproved clutch presenting such a long gripping-surface, a dent orenlargement on the lamp or carbon rod will not affect the properoperation of the clutch in the least. The free end of the clutch-lever 3is pivotally connected to an arm 0, which latter is pivotally connectedbetween the lugs or ears '5 on the shaft g, the clutch-lever thus beingin effect connected with the armature-lever E. To the saddle 1 of theclutch a trip-arm 10 is connected and adapted to engage the bottom plateA of the lamp or a plate 11 secured thereto to release the clutch, ashereinafter explained, said trip-arm havin an elongated slot 10 for thereception of a screw 10 ,whereby to admit of the ready adjustment ofsaid trip-arm.

In the diagrammatical view, Fig 1, the carbons are shown separated, aswhen the lamp is not burning. \Vhen the current is switched on, its onlypath will be through the fine-wire magnets, which at once draw up theweighted armature E, slowly lowering the clutch and carbon rod until thecarbon points come into contact. If the trimming of the lamp is regularthe carbon points will come together before the clutch releases thecarbon rod. Consequently the carbon cannot lap, (a common trouble withconstant-potential lamps.) The instant the points touch a path for thecurrent will be closed through the helix of the coarse-wire magnet F,which latter will attract the armature F (overcoming the pull of thefine-wire magnets E) and lift the clutch, which again separates thecarbons and establishes the arc. The pull of the fine-wire magnets isnearly constant and the strength of the coarse-wire magnet varies withthe resistance of the arc. As the carbons burn away, the resistance ofthe arc increases, and conse quently the current flowing through thecoarse-wire magnet decreases until the finewire or shunt magnetsovercome its pull and slowly lower the carbon rod, thus maintaining thearc until the trip-arm 10 of the clutch reaches the plate 11 or thebottom plate A of the lamp-frame and releases the clutch. This allowsthe carbon rod to slide downwardly a little, but it will be instantlycaught and raised by the clutch, because'the approach of the carbonstoward each other allows an increased current to pass through the coilof the coarse-wire magnet. IVhen the carbons shall have been consumed,the circuit will be opened at the arc of the first pair of carbons (whenseveral lamps are in the circuit) that can feed no more, and the carbonsin another lamp that are notyet consumed will continue to touch andspark slightly, thus indicating that it is the dark lamp which needstrimming.

No harm will result if lamps are allowed to remain untrimmed and theonly loss will be the slight current passing through the finewire coilsuntil the current is opened atthe switch. Experience has shown that nocutout is needed, as the resistance of the fine-wire coils is sufficientto prevent burning out in case of accident to the carbons.

My improvements combine in the produc tion of an electric-arc lamp whichis simple in construction and effectual in all respects in theperformance of its functions.

Various slight changes might be made in the details of construct-ion ofmy invention without departing from the spirit thereof or limiting itsscope, and hence I do not wish to restrict myself to the precise detailsof 0011- struction herein set forth; but,

IIa-ving fully described my invention, what I claim as new, and desireto secure by Letters Patent, is

1. In an electric arc lamp, a clutch comprising a saddle adapted to bearagainst the carbon rod and having ears projecting beyond the same, abifurcated lever pivoted be tween said ears and a shoe pivoted in saidlever and adapted to bear against the carbon rod, substantially as setforth.

2. 111 an electric arc lamp, a clutch comprising a saddle adapted toembrace the carbon rod, a clutch lever having a bifurcated end pivotallyconnected to said saddle,a clutch shoe pivoted in said bifurcated end ofthe lever, said shoe having a slot made larger at one end than at theother, the pin which pivots the shoe to the lever passing through thesmaller end of the slot and the pin which pivots the lever to the saddlepassing through the larger end of the slot, substantially as set forth.

3. In an electric arc lamp, a clutch comprising a saddle adapted toembrace the carbon rod, a clutch lever eccentrically pivoted to saidsaddle, and a clutch shoe pivoted to said lever, substantially as setforth.

4:. In an electric arc lamp, the combination with a carbon rod, anelectro-magnet and an armature for said electro-magnet, of a clutchcomprising a saddle adapted to embrace the carbon rod, a clutch levereccentrically pivoted to the saddle, a connection between said clutchlever and said armature, and a clutch shoe pivoted to said clutch lever,substantially as set forth.

5. In an electric lamp,the combination with the chimney thereof of ametallic tube located therein and constituting a conductor, and aresistance coil inclosing said tube and insulatedtherefrom,substantially as set forth.

6. In an electric lamp the'combination with a metallic tube, of aresistance coil inclosing the same and insulated therefrom, an elasticplate having a slide wire contact with said resistance coil, and aconductor for connecting said plate with one end of the resistance coilin such manner as to permit the elastic plate to be moved about saidcoil to take up slack of said conductor, substantially as set forth.

7. In an electric arc lamp the combination with a frame and a chimney,of a tube secured to the frame and extending through the chimney andhaving a screw threaded upper end, a flaring ring at the upper end ofsaid chimney, a cap having a bearing in said ring and a nut on saidscrew threaded upper end of said tube bearing on said cap, substantiallyas set forth.

8. In an electric arc lamp, a clutch comprising a saddle adapted toembrace the carbon rod, a clutch lever having a bifurcated end pivotallyconnected to said saddle, a clutch shoe pivoted in said bifurcated endof the lever, said shoe having a square cornered slot made larger at oneend than at the other, the pin which pivots the shoe to the leverpassing through the smaller square cornered end of the slot and the pinwhich pivots the lever to the saddle passing through the larger end ofthe slot, substantially as set forth.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

THOS. E. ADAMS.

Witnesses LEWIS H. RoeERs, A. D. DORMAN.

